Method of making cyanamids.



No. 686,950. Patented Nov. 19, l90l. J. PFLEGER. METHOD OF MAKING GYANAMIDS.

(Application filed Mar. 15, 1001.) (N0 ModeI.)

V/IIIIIIIIIIIIIJ 9 SM vaufoz wfnoomo W M we NORRIS Farms cu. PHQYO-l 1M1. WASHINGTON, nv c UNITED STATES PATENT OFFICE.

JOIIANNES PFLEGER, OF FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNOR TO THE FIRM OF DEUTSOHE GOLD & SILBER-SOHEIDE ANSTALT, VORM. ROESSLER, OF FRANKFORT-ON-THE-MAIN, GERMANY.

METHOD OF MAKING CYANAMIDS.

SPECIFICATION formingpart of Letters Patent No. 686,950, dated November 19, 1901. Application filed March 15, 1901. Serial No. 51,417. (No specimens.)

To all whom it may concern:

Be it known that I, JOHANNES PFLEGER, a subject of the Emperor of Germany, and a resident of 215 Gutleutstrasse, Frankfort-onthe-Main, Germany, have invented certain new and useful Improvements in the Mannfacture of Cyanamids, of which the'following is a specification.

In the specification of my application for Letters Patent, Serial No. 39,383, of the 10th of December, 1900, is described the manufacture of cyanamid by subjecting the cyanid of an alkali metal to the action of the amid of an alkali metal. I have since discovered another method of preparing cyanamid-for instance, dialkali cyanamid-which method is based upon the fact observed by me that at the comparatively low temperature of 300 to 400 centigrade carbon acts on the amid of an alkali metal in such a manner that the whole of the hydrogen of the amid is replaced by carbon in accordance with the following formula:

whereas at a higher temperature (about 800 centigrade) NaOy is formed directly from the amid of the alkali in accordance With the following formula:

In lieu of solid carbon--such,for instance,as charcoal-other carbonaceous substancessuch, for example, as a carburet of hydrogenmay be used, which contain the carbon mechanically or chemically combined and are capable of yielding it up to the amid of the alkali, and thereby forming cyanamid.

The accompanying drawing shows a melt- 4 ing vessel in sectional elevation in which my process may be carried out.

In the drawing, a is the vessel, 1) the charging-opening, and c the tube, which may be used for passing ammonia into the vessel.

The process according tothe present invention may be carried out in various ways. For example, as applied to the preparation of the disodium-cyanamid the proceeding may be as follows: Sodium amid, which may be prepared in the usual way, is melted in a suitable 5o vessel, as shown in the accompanying drawing, and carbon added to it at about 350 centigrade. The reaction takes place at once Wit-h a brisk disengagement of hydrogen. As the melting-point of the sodium c'yanamid is about 550 Centigrade, the temperature must,

as the cyanamid is being formed, be raised until it finally reaches between 550 and 600 centigrade, or sodium may be melted in a suitable crucible and the amount of carbon required for the formation of the cyanamid be introduced into the molten sodium and ammonia be passed through the mass. If the temperature on starting the operation be 400 centigrade and the temperature be gradually increased until it is slightly above the melt ing-point of the cyanamid, the carbon acts at once on the amid of the alkali metal as it is being formed. In this process cyanamid and no cyanid will be formed, and in the example given disodium cya mid will be formed.

Other alkali met s may be used in place of sodium, the te peratures to be observed varying accordin ly. Instead of solid carbon liquid or gaseouzbodies containing carbon may be used, these latter being blown into the molten amid of the alkali metal or into the molten alkali metal itself.

1. The process herein described of making cyanamid, which consists in reacting alkali amid with carbonaceous substances while maintaining the mass at a temperature suitable for the production of cyanamid, Whereby cyana'mid is formed from the above sub stances in accordance with the equation substantially as and for the purpose set forth.

2. The process herein described of making cyanamid, which consists in reacting alkali amid with carbonaceous substances while maintaining the mass at a temperature of about 350 to 600 centigrade, whereby cyanamid is formed from the above substances, substantially as and for the purpose set forth.

3. The process herein described of making 1 name to this specification in the presence of cyanamid, which consists in reacting alkali two subscribing witnesses.

amid with such proportions of carbonaceous *1 substances and at a temperature of 350 to JOHANNEb PFLEGER 5 600 centigrade as to produce cyanamid, sub- Witnesses:

stantialiy as and for the purpose set forth. JEAN GRUND, i

In testimony whereof I have signed my CARL GRUND. 

